Hi stuckfree,
Magnets are used in computers for various purposes, for instance in hard drives. Many parts of a computer/laptop can be affected by a magnet. The most commonly referred to piece of hardware affected by magnets is the hard drive.
This is not exactly true. Hard drives are well protected against most magnetism, and most even use a magnet to spin, but many strong magnets and electromagnets can and will damage a hard drive. More likely to be affected is your computer's BIOS (Basic Input\Output System) ROM, which tells your motherboard how to use basic components and boot into the Operating System.
So it is better to avoid placing computers\laptops close to any such appliances.